Production of monosulfonated carboxylic acids and their esters



PRODUCTION OF MONOSULFONATED CAR- BOXYLIC ACIDS AND THEIR ESTERS WalterH. C. Rueggeberg, Atlanta,

College Park, Ga., assignors to Tennessee Corporation, New York, N. Y.,a corporation of New York No Drawing. Application June 24, 1953, SerialNo. 363,934

6 Claims. (Cl. 260-406) and Thomas W. Sauls,

This invention relates to a process for the production of monosulfonatedunsaturated carboxylic acids and their esters. This application is acontinuation-in-part of our prior application Serial No. 291,328, filedJune 2, 1952, now abandoned.

Because of their surface active properties and extended use as wetting,rewetting, emulsifying, dispersing and similarly used agents in thetextile as well as in numerous other industries, sulfonated oils havebeen known and manufactured for a long time. In prior patents andliterature pertaining to this subject, however, the term sulfonatedoften has been erroneously applied to materials which are the additionproducts of sulfuric acid to an olefinic linkage or the reaction productof an alcohol with a sulfating agent such as H2804, oleum, S03, orClSOsH. These, latter types of materials are really esters of sulfuricacid, i. e., they are sulfates rather than sulfonates, the latter termbeing properly applied only to those materialscontaining a direct carbonto sulfur linkage. These two types of materials can be represented bythe following formulae:

( ioso,-o-n

a sulfate, or alkyl sulfuric acid (2) (:J %-SO -OH a sulfonate The alkylsulfuric acids, or sulfates, are soluble in water and, if thehydrocarbon part of the molecule is sutficiently large (Ca to C20),exhibit surface activity. Examples of such sulfates are:

(3) The addition products of H2804 at an olefinic linkage, as in thecase of sulfated esters of unsaturated fatty acids such as propyloleate.

(4) Products formed by reaction between a sulfating agent and an Oi-Igroup, as in the case of sulfated castor oil.

onaonmcn-om-on=on om)1000R -s o -on Where R represents one-third of aglycerine molecule, the other two-thirds being usually esterified withunsulfated fatty acid.

(5) Products formed by reaction between a sulfating agent and theterminal --OH groups of long chain alcohols, as in the case of sulfatedlauryl alcohol.

Sulfates of the above types are usually used as salts, most frequentlyas sodium salts. In many cases, however, such sulfates or their saltsare undesirable because of their instability toward hydrolysis and heat.If such an ester of sulfuric acid is permitted to stand in water underacidic 2,743,288 Patented Apr. 24, 1956 2; conditions, decompositiontakes place yielding an inorganic sulfate and an alkanol, thedecomposition being accelerated by heat:

acid or oleum is used as a sulfating agent for olefins or alcohols, anexcess of the sulfating agent is required to obtain practical yields ofthe sulfated product in most instances. When neutralized, this excessbecomes sodium sulfate which is undesirable in many cases, but it isdiflicult and costly to remove either the excess sulfuric acid from theunneutralized sulfated product or the NazSOs from the neutralizedsulfated product.

A much more desirable configuration for these types of materials is thatwhere true sulfonation exists, that is, where there exists a carbon tosulfur linkage of type (2), because hydrolysis of the sulfonic acid orits salts is impossible under nearly all conditions of acidity andbasicity and over a wide temperature range. Thus it has been proposed toproduce stable carbon to sulfur linkages at the double bond ofunsaturated materials by means of the well known carbyl sulfatereaction. This reaction, in order to obtain a high yield, requires atleast two moles of S03 per mole of unsaturated material. tion can beexpressed as follows:

The carbyl sulfate can then be hydrolyzed to give a sul-' fonate-sulfateas follows:

Under more vigorous conditions the sulfonate-sulfate grouping can befurther hydrolyzed to a hydroxy-sulfonate as follows:

It will be seen that products of types (6), (7) and (8) each contain acarbon to sulfur linkage, but also that addition has taken place at bothcarbon atoms at the double bond, requiring two moles of S03, and thatunsaturation has disappeared. These products and their sodium and othersalts possess surface activity and wetting properties, but in generalare inferior in these respects to well known and widely used sulfatedoils (e. g., Twitchell oils), while their preparation is more complexand excessive amounts of sulfonating agent are required.

We have now discovered that when unsaturated carboxylic acids arereacted With sulfur trioxide dissolved in liquid sulfur dioxide, theamount of sulfur trioxide being limited to 1.0-1.25 moles per mole ofunsaturated acid, a very high yield of monosulfonated unsaturated acidis obtained. Under these conditions S03 reacts with only v one of thecarbon atoms at or near the double bond and with its attached hydrogenatom to form a true sulfonic Carbyl sulfate forma-- Although directanalysis of the product is somewhat difiicult it can be achieved byutilizing a combination of methods consisting of determination ofunsaturation using Standard bromine addition technique, determination ofhydroxyl groups present by acetylation, and elemental analyses forcarbon, hydrogen and sulfur. Hydroxy sulfonic acids can be formed eitherthrough the carbyl sulfate reaction of Formula 6 due to excess S0 used,or through the addition of the intermediate product of Formula 10 to thedouble bond as follows:

of the amount of monosulfonated unsaturated material. The followingtable shows the results thus obtained in the case of monosulfonatedoleic acid:

Weight lzveight ll vcight l\l/gercentl ercen ercen onosu Mme g? 0161cDisulfurized Hydroxyfonated Product, sulionatcd Unsaturated found Acid,found Acid (by difference) As another example, neutralized oil-freemonosulfonated undecylenic acid may be expected to contain as high as91% unsaturated sulfonate.

Based on the elemental analyses and the percentages of hydroxy sulfonatefound, the composition of the final product is as follows:

Hydroxy sultonate found 28.3 wt. percent.

Consequently the product may contain, in addition to the predominantunsaturated monosulfonated oleic acid, a'smaller amount ofmonosulfonated hydroxy stearic acids believed to have the following orsimilar structures:

(13) onuomnonwmornuo oon HO 020K 14 on. om)1cn-on on.)1o 0011 Thus inthe case of monosulfonated oleic acid the neutralized, oil-free productcontains 25-30 weight percent of hydroxy sulfonate.

Also it can be seen from the above data as to Runs 1, 2 and 3 that theamount of organically combined sulfur is slightly greater than one moleper mole of oleic acid, indicating the presence of minor amounts ofdisulfurized material, probably sulfonate-s'ulfates, and that the amountof this disulfurized material increases as the amount of excess S0 isincreased above one mole per mole of oleic acid.

Experience has shown that only about 60 90% of the unsaturation presentis detectable by.Wijs method, and that experimental determination of thehydroxy monosul-- fonate content and of the excess sulfur content of theneutralized oil-free product is a more reliable indication Based on thecarbon and hydrogen analyses, the following is the composition of theproduct:

Weight Percent;

- Percent Percent Compound No. percent in H dro- Pmduct Carbon g Sulfur54. 3 28. 89 4. 31 4. 28 28. 3 14. 42 2. 28 2. 14 17. 4 7.14 1.10 2.12Total 50. 45 7. 69 8. 54 Total found 50. 45 7. 97 9. 11

Combined $03 to oleic acid ratio=1.0 to 1.1; found independently by S0;consumption=1.06 to 1.09 (see above).

It can readily be seen that there is excellent agreement betweenelemental analyses for carbon, hydrogen and sulfur found and those basedon the composition. There is equally good agreement between the combinedSO /oleic acid ratio found by elemental analyses compared with thatfound by the S0 consumption in the synthesis.

It will be seen from the above data that the amount of unsaturatedmaterial retained in the product is better than 50 weight percent; asshown above, moreover, the hydroxysulfonate present is the result of themonosulfonation procedure instead of disulfonation followed byhydrolysis of the sulfate radical as is normally assumed. The productcontains only 17.4% of disulfurized material, the remainder of 82.6being monosulfonated, and about 66% of the monosulfonated portion beingstill unsaturated.

When neutralized withone .rnole of base, o lyathe V SOiQI-Lgroup of thesulfonatedaci diis-transformed into a salt since this group,is.much.more=.sti:ong1y acidic than the COOH group. Aqueous solutionsof these mono salts exhibit -good .surface active -characteristics .andwetting, timestas stated above. For example, in the case ofthemonosodium salt :of monosulfonated oleic acid, Wetting timeslforvariou'sconcentrationin water: are-:shownsin the following table: I

. -Wetting Times (Braves Test) in seconds Gone, Percent Naflalt iOleiclSulionic Acid lt will 1 be .evident that tl're monosulfonatedunsaturated acid can be neutralized withiany other rdesired base, in-

7 organic or organic, so as to produce mond'salts of the monosulfonatedacids with varying 'solubilit-ies in water and otherpsolvents andvarying wetting'characteristics as may-'bepreferred forparticular uses.Thus, for example, the potassium, ammonium, monoethanolammonium,

triethanolammomum,wetc., salts of monosulfonated oleic i '9t mies. guing h ;-nrlonosultnnatedvlestens .ZithNaQHor other.

l bases such as..NHa, ,-.KQH,.;a1kanolamine, vote. name 9 acid wereprepared and were found to possess the following wettingcharacteristics('Draves test) 'i'n- 0.-5 aqueous solution at room temperature:

Vg etting unes Mono Salt of Monosulionated Olerc Acid Dmvzsx secondspotassium,'K+ 21 ammonium, N'Hi 18 monoethanolammomurn,HOCHzOHzNfiIi. 20triethanolammonium, (HOCH'gOHzhbHH..- sodium, 'Na+ (for comparison) 8Although .as alrcadystated the esters of the unsaturatedoarboxylic-acids cannot be. monosulfonated in the above describedmanner, we have discovered that the free monosulfonated acids themselvescan readily be -esterified at the carboxyl group with a wide variety ofalcohols, including primary and secondary monohydric 'and 'polyhydricalcohols, substituted or not, yielding. monoslilfonated esters havingvery desirable'properties. "The "desired alcohol-'canibeadded directlyto the sulfonation mixr ture, or the'SOz may'firstberemoved'from'thejlatter.

Preferably the bulk of -the SOa is first removed'by -warm .ing thesulfonation :rnixtureto a temperature of about 5" *C-10 C. No externalheating-or cooling is -required tor .the. :esterification, .but' thetemperature of "the 'mass will rise somewhatdue to-heat'of reaction."usingfonly tion reaction.is-p ractically.complete. in abouttwohoursunder these conditions, and the time required :can be greatly reduced byusing larger amounts "of alcohol as shown'hereinafter. The 'yields ai everyhigh (90-95%) and :esters :of high purity and quality are obtained;Analysis shows these esters to zcontain :no organic. S02; as-sulfate,all .of :the S03 beingxsulfonate'a-s in 'ithe case of the-freemonosulfonatediacids.

"Whenit is desired to'use larger amounts rof an aleohol ample, thefollowing table shows the results at wetting tests (Draves) with aqueoussolutions of the sodium salts of yaiiious-esters-mf monosulfonated oleicacid nf 0.1% concentration in water at room temperature:

Ester: Wetting time, seconds Methyl 25 Ethyl 9 n-Propyl 5 Iso-propyl 12n-Butyl 5 n-Amyl l2 n l-lexyl 2'8.

Remarks: Optimum size of ester chain is n-propyl or n-butyl. Iso-'propyl ester is less efieetive than n-propyl ester.

fl he -monosulfonated esters of unsaturated carboxylic acids'also retaintheir excellent wetting characteristics in acid and basic media and inhard water, as shown in the -iollowingfltable for the n-propyl ester ofthe sodium salt of monosulfonated oleic acid:

- Wetting Time, seconds (Draves), in- Percent Oleate D istd Water HardWater 2% H1304 1% NaOH 73 130. 16.-. 30. 0.10 6-- 9. 0.20 1.5 1.5. 1.-2.5. 0.50 less than 1.. less than 1.. less than 1.. less than 1.

1 390 p. p. m. hardness.

Asidefrom possessing good wetting characteristics, esters, of the above.types are structurally suited as Twitch6Il type reagents and asrewetting agents used in'thesanforizing process for cotton. For example,the

' napropylzesteriofttheisodiumzsaltzofzmonosulfonatedmloic aeidihas zamutating-amnion seconds whenwused in a concentration "of mo on 116seconds whenused in ia-lzorrcentratinn of :%ron,:cloth *.('AATCCQP'tfl8t')-. In some instances dark ester products may be encountered,especially asa result of using low-grade starting materials suhs lowgrade'ole'ioacid containing polyunsaturated carboxy'li'c mcidsgor talloilfatty'acids.

' a slight excess ofaalcohol, say 1.25 .nioles, 1116 zesterificatoeffect the esterification, the recovery of excess aico- 1101 used:becomes economically attractive. Ellis-reco 'ery .can be satisfactorilyaccomplished bymdistilling ;the

alcohol together 'with water, :after neutralization-as 116--scribedabove, preferably-as an jazeotrope.

Thusdn the case of 'n-propanolesters, the excess i-nfpropanol can berecovered as can azetrope "with z-water boilingmat .-,87. I

It has been found that such products can be efiectively bleached andimproved in odor by neutralizing thejesters to only"ab'out pH 6-7 withcaustic or other basean'd then continuingithe(neutralization .topH-h bymeans of. a hypochlorite. Sodium hypochlorite solution,

others, is especially eife'ctive. This procedure, for unknown reasons,produces better bleaching than when the bleaching ngent'iis added .to amonosulfonatedester of V a :carhoxylic acid first sneutralized -to ,pH.-8 by caustic or other base. r a l Furthermore-tit may ibedesirableinsome instances to ;extract itheamonosulfonated:-acid or its ester from.un reacted crnatcrialafi-alth'oughgfor .many ,purposes .this isunnecessary because-rot: the :s'mall amount of the latter. whemextiacdonisidesincdnb fl; t sulionatedmatei the unreactod oilymeteriala-areseparated by means ofa suitable oil solvent such as petroleum ether,asaturated C..,=b.eing'composed=of 28% 'water and 7'2%rn+propanol.

:For' obvious economic reasons it becomes "of :intere'st to use"mixtures containing"72-'l5 n propano'l and 25 hydrocai'honsolvenhmc 1':In :eontrast *toithe excellent, unanticipated .results .ob-

tained rwith-wsters -pippared z-as described a above, v very in:

fetiorcoimjwndsfmcwbtained-by the ectionotas ij 7 among directly on theesters of the unsaturated acids. When $03, per se or in a solvent or asoleum, is allowed to react with such esters, the carbyl sulfate reactiontakes place as described above, requiring 2 moles of S03 per mole ofunsaturated acid to yield a high degree of sulfonation. One mole of 50sreacted with one mole of the ester of an unsaturated fatty acid willresult in only 50% or less conversion, in contrast to the nearcompleteness of reaction observed when the free unsaturated fatty aciditself is used with S03 in S02. These facts are illustrated by thefollowing table: SULFONATION F n-PROPYL OLEATE WITH VARYING AMOUNTS OF$03 Moles Percent of Run No. Moles SO; Propyl Total Oil Oleate bSulfonated Runs 1, 2, batchwise.

II Minimum purity, 90%.

3, and 4 were made on spinning disc. Run 5 was made Rewetting Time,

etting seconds n-Propyl Oleate Sultanate-Sulfate Time,

sseonds, 1 7 3W 0. cone on on 0 oiom oioth Sample 20) 17. 4 40. 6 8. 8Sample 40) 40. 6 68. 0 23. 2

5 From Run 2, preceding table.

i FromRun 4, preceding table.

In contrast, the sodium salt of the monosulfonated npropyl oleateprepared by the previously described process of esterifying themonosulfonated oleic acid with npropanol has a wetting time of onesecond or less under the same conditions.

Analytical data have shown that these sulfonated-sulfated derivativescontain an amount of combined S03 about halfway between the theoreticalvalues for the saturated monosulfonated hydroxy derivative (Equation 8)and the sulfonate-sulfate (Equation 7). Thus, in the case of then-propyl ester the S03 content was found to be 25.0%. Thehydroxy-sulfonate has a theoretical S03 content of 18.0% whereas thesulfonate-sulfate has a calculated S03 content of 30.5%.

The following examples illustrate the method of preparation of themonosulfonated products described above:

EXAMPLE 1 Monosulfonation of oleic acid One hundred seventy-five gramsof a commercially available grade of oleic acid containing less than 5%polyunsaturated acids and about 810% saturated fatty acids, togetherwith 62.5 grams of S03, dissolved in 468 ml. of liquid SOz, were runonto the surface of a spinning disc sulfonator at equivalent rates fromseparate feed tanks, as described in the aforesaid pending application,Serial No. 182,730. The reaction takes place very rapidly underatmospheric pressure and at temperatures in the neighborhood of 10 C.

After the very rapid reaction was completed the reaction mixture wasstripped of sulfur dioxide until the temperature of the crude reactionproduct had risen to 10 C. Subsequently, 50 ml. of water were addedwhile simultaneously bringing the temperature to 40-45 C. by means of ahot water bath or other convenient means of externally applied heat.Good agitation was continued for 15 minutes to expel most of theremaining sulfur dioxide, and air was then sucked through the systemunder vacuum from a water aspirator pump for 15 minutes to removeresidual sulfur dioxide. At this point the aqueous acid was a viscousdark brown material. To prepare the monosodium salt of themonosulfonated oleic acid 31.3 grams of sodium hydroxide dissolved inml. of water were added. The pH of the final solution should be adjustedto about 5 or 6 to insure complete neutralization of the sulfonic acidgroup. At the end of this period the mixture was of a clear reddish toorange color.

As shown in the preceding description, the product produced by the aboveprocedure has good surface active properties and wettingcharacteristics; also the substitution of other bases for NaOH forms anydesired mono salt of the sulfonate, either organic or inorganic. Thesematerials are marked by unusual stability in neutral, acid or basicmedia, hot or cold.

If desired the mono salts obtained by the above procedure can bepurified by extraction of unsulfonated oils, as illustrated by thefollowing example. One hundred fifty-one grams of a 50% aqueous solutionof the monosodium salt of the sulfonated oleic acid prepared in theabove manner was extracted with 200 ml. of petroleum ether. Aftervigorous shaking, the thick emulsion broke rapidly into two cleanlayers. The first petroleum ether extract contained 6 grams ofunsulfonated oil. A second extraction with 75 ml. of petroleum etheryielded 1.3 grams and a third extraction produced only 0.8 gram ofunreacted oil. The extracted unsulfonated oils were apparently rich instearic acid since after removal of the petroleum ether a solid, waxy,fatty acid was left behind. After removal of the petroleum ether fromthe aqueous layer containing the Na salt of the sulfonated oleic acid, aproduct was obtained which produced clear solutions even in hard waterof 300 p. p. m. hardness.

EXAMPLE 2 Monosulfonation of dimerized linoleic acid Dimerized linoleicacid, commonly referred to in the industry as dimer acid, is by nature athick, tacky, dark colored oil and is supposed to have the followingstructure:

188 grams of dimer acid were thinned by diluting with 40 ml. of diethylether. 31.4 grams of sulfur trioxide in 484 ml. of liquid sulfur dioxidewere added at equivalent rates from separate feed tanks onto thespinning disc sulfonator. This amount of S0: was equivalent to 1.25moles per mole of dimer acid. The sulfur dioxide was removed afterreaction as described in Example 1. Then 50 ml. of water were addedwhereupon the temperature reached 10 C. The temperature was then raisedto 50 C(for 15 minutes by the application of external heat and theproduct was swept free of residual sulfur dioxide by means of a currentof air supplied by the vacuum of a water aspirator pump. The addition of18 grams of sodium hydroxide dissolved in 65 ml. of water brought the pHto 5-6. The residual ether was distilled off and the remaining thickliquid was poured from the flask and allowed to stand for several daysin a glass bottle whereupon another small water layer separated whichwas drawn off and discarded. The final concentration of the sodium saltof sulfonated dimer acid was about 75%. It was found to be soluble intap water producing an opalescent solution. The wetting time of 0.5%solution (Draves test) at room temperature was 7120 seconds. This highttall oil .fatty-r acid h-avin g .the following -icrnposition egas aasvalue is to the ieigpected :because ;of sthe ilarge (size of .the 7molecule. rewettiog time (AATTQdrop Jest) was :75

secondsforl%son.clo.thand.3:8 seconds-;for:.3% oncloth- Asiinuthe aboveexamples; neutralization .of the sulfonic V tcantbedone withinorganicvvorrorganic bases-by subzstitutiontfor ,NaOH in theneutralization step.

EXAMPLE-3 a '-,Mo1i0stlfonati0n oj tall oil jattyacids mid Jaw (grade "Asample of cornmerciallyavailahle tall oil fatty acid having'thefol-lowingapproximatecomposition,

waststflfo ated in a manneridentical with that u scd .lfor

.oleieaciddn-Example :1. :Avconversionof 75%\.resulte,d. I

lhe wettirlg times and surface Eactivity -.o.f an aqueous solution\ofsthe monosodium .salts of .this mixture of sultonated' acids werevery goodzthoughi-somewhatinferior tQHflIB PI' ZQdHCt obtained {from tapurer -grade .ot oleic :acid QExample i 1;). r r p Similarly, vanothercommercially available sample of i A V 7 Percent Dleic-a-cid -'46Izinoleic ..39 v 'lsinolenic acid, 23 Rosin 12 r 12monesulfonatedterotonic acid was further purifiedslgy dissolvingsit ,irr95, acetic acid; which served -.to remove the remaining-inorganicmatter. The filtrate containing 3 sul fonated crotonicacidlderivative was :freed of acetic .acidzaud itherresidue dried intanzoven. Analysiseshowd that1t'he .productcontained 35.6% '80s, thetheoretical for ,the anhydrousldisodium sa1t being.38.1 andi or flzc-,monohydrate:being 35.0%.. Ihis 'amounteditoaconversionof lcrotonicacid to zthe ,nionosulfonated derivative {of ss .90r%. I i V Bases,other than,:N.aOH-, both inorganic and organic,

such as NHs, KOH, alkanolamines, etc can 'be used in p 7 7 placeof'NaOI-I'toneutralize 'Ihemonosulfonate of cro V tonic acid.

p 7, Percent Wale-acid ....Q L50 7 Einiileic'*ac'i'd (iii-unsaturated).4 40 Linolenic acid-{tri-unsaturated) -4 jRo'sin tcliiflyyabieticacidtype) 6 EXAMPLE 5 MOrlOSlllfOlttlfiUlL of undec'ylenic acid(IO-undecene I-oic acid) (CH2=CH(CH)COUH) 42.9 gramis of S03dissolved-in -200mlr of liquid were added'in 5.5 minutes 'to'78i5 gramsof undecylenic acid dissolved in 300 m1. COz-contained in a lliterroundI 'bottompyrexflask, After completion-ofrthereaetion-flae bulk ofthe'sOz was removed rby stirring thefiproductm'rik wasjsulfonated asdesfcri bed in Example ",1. The results offpe'rformance tests of thismixture of .sulfonatedproduets' were as good as those obtained withjiall ofil fatty acidsiconta-iriiu g only 6% rosin. 7 V. 1

Similarly, grades of soleic acid;,poorer 'in quality than thatdescribedLin33xample l canbe used .in this ,'process.

suen ,poorer grades ziof .oleieacid. usually contain quanti'ties of diand polyunsaturated acids Tin. excess of 5%. A 0.5% aqueous solution ofthe monoso'dium salttof'this monosulfonated acid had a wetting time ofseconds (Dravesutcst) at. room.:terrgperature compared with 8 secondsfound for the product derived from a purer grade of oleic acid (ExampleI).

' taxis-Miam V Monosulfonizti on of crotonic acid ('GHaCH -"CH-GOOH-) VI V V Eighty-five grams of commercially available Tcrot'onic 7 acid weredissolved in 250 ml'xofiliquid sulfur-dioxide in a three niecklrouridzhottom flask. .v9 8.81;gr-ams.oflsulfurztrioxide-.dissolved31in5250,1111. of asulfuradioxide Mas Jdropped illtfixthficSQZ 5Q111fi01110 crotonic acid during: a9 minute,zperiod. .Little;reaction was'apparent. The solution-retaineda-jlightstrawicolor. v The bulk of the SOwwasevap- '1 mated :atter-.addit-ion of the .SQ: {by running tap water overthe outsideof,the,flask and the-:temperatureof .the' reactiommass was-brought upslowlyto UC. by means of ELW=W8IXT1 water bath. .'At :this point thetemperature molecular; vweight unsaturated acids; -After theLreactionhadssubsided and .the temperaturehhad fallen to about A0 C,,.1 O0;ml.:ofwater-was slowly added, dropwise, with Stirring Qf;the;reaction,mixture.49;5rgrams of sodium hydroxideedissolved in 15.0. ml. 70f water was.then added slowly andnthe, finalcleansolution, having a pHtof 2,was

extracted twice with 250-ml.;;portionslof .diethyl ether.

ture and simultaneously running water over the of thelfiask. Whentheitemperature' reached 5 C. solidification of -the 1 products"resulted and "subsequently 200 ml. of'wat'er were added, with1ittle'orno generation of heat; The "aqucous'p'roduct' 'so'lution'iwasheatedtoiboiloxide. Then "theproduct solntiontwas coolcdtoSOT).

V whereupon about one gram of resinouslay-product precipitate'd whichwas removed. "The clear solution was extracted with 2 portions 150an'd75 ml, respectively,--of petroleum ether. 'Thistreatment resultedin"theextraction of only"2.2 gramsoit' unsulfonated material. The

' aqueous solution was then neutralizedrto ;pH-4=5 with 21.5. grams ofvsodiumhydroxide in ml. of water. Onefour'th of;thezneutralized liquidwas neutralized further to --pH 9-10. This neutralization required 42.8grams sodiumfhydroxideavhich is nearly ,the theoretical quagf and nearly'l' 60%-of theory'based on the monohydrate.

' resewerymapidlyto90+1Q0iCrdueitoeheat-tofireaction. a

Apparently/, crotonic :acid isless reactive than the \higher 7Evaporationiof=the:ether-showedthat lOggramsaofian unreacted materialhad been iextracted. 41.5 grams 101545.0-diunuhydroxidesdissolved;in150.mlqofxwater were added 'toebringtheyreactionmixturestogJH9. lhezsolution-iwas evaporated ,to drynessrand the crude ldisodium salt of Bases both inorganic andyorganic canfor' NaUI-l to produce ta variety o'f s'alts- V Trep tiqn o'f carbaxylicacid esters of imonoszfllfa'n a'ted I V V 'oleic acid I p v:.Qleicacidxwas 1su1fonated ;as ,in .Exarnple -;1' an azdisc sulfonator:orabatehwise. 7 After "111C @sulfonation reaction was complete and whenthe bulk-Lot" the sulfur dioxide had been driven off 'andthetemperature'had'reached 10 C., 5 molessofjhegdesinedalcohol-were added and a themixture allowed to stir for 2 hoursQ No external heat:

or ecooling was applied during this period. T The ternperature. rosetteabouti 3540 ,C. due to the heat ofjreaction. At the'eridloi;this,-2.hourperiodthe mass was'sweptifi minutescbyppulling ,air, through the mixtureto-iremove re'si'duallSQg, using the waterpump 'Iorsuction, The' acidwas thenwneutralized' byfla'dding a"25% iNaOH sohition kceping thetemperature ;u1ider" 35 ICnwith an iceibathi. ,Qneslmole "of INa'QH ,permole SO s'u'sua'lly brought 21h:

pH to 7-8.

.RemoYaLof -the excess alcohol was accomplishedby distillationtatLatmQsphericpreSsure,"'the pot teirgperature not being allowed toexceed 105 C. In most cases additional water had to be added to distilloff the azeotrope, alcohol-water. After distillation the pH usuallydropped to 5-6, but only a small amount of NaOH was needed to bring thepH back to 8-9. For purposes of consistency and comparison all productswere adjusted to a 50% water content after distillation andneutralization, although any concentration in water up to at least 80%of sulfonated product can be obtained by this process.

Wetting times for a number of diflierent esters of monosulfonated oleicacid prepared in the above manner have already been set forth.

These products were also analyzed for oil by the customary methodpreviously mentioned, i. e., by extraction of aqueous solutions withpetroleum ether. In some cases a little methanol had to be added to theaqueous solution to cause a clean separation. The petroleum ether layerwas washed with water to remove traces of water-soluble material. Apinch of NaCl helped break the layers. The following table summarizesthe results 20 obtained of these analyses:

10 It will be understood that the esterification conditions described inExample 6 can be varied widely with respect to the amount of alcoholused and the time and temperature of esterification. In general, lowermole ratios of alcohol to acid present the advantage of having little 15or no alcohol to recover, whereas higher mole ratios usually yieldsomewhat better products as to color and Wetting time and permitesterification to be completed in a shorter time with somewhat less oilin the finished product. Nevertheless excellent products can be obtainedunder widely varying conditions of esterification, as illustrated by thefollowing table which shows the effect of ESTERS OF SULFONATED OLEICACID Esterlficaticn on in 507 Gms Gms Gms Gms. Gms. Conversion A ueous"Nature of Alcohol Uscd Olcic Alcohb] NaOH to 120 in to Ester, Pgduct 50%Acid pH 8 Run 'lgme, 'le rlp Percent Percent Product 54. 8 155 80 29. 9231. 7 2% 25-43 90-95 8. 4 liquid. 53. 2 150 122. 5 27. 58 233. 7 2%28-41 90-95 7. 6 D0. 46. 97 144. 6 165 26. 226 2% 25-38 90-95 8. 0 D0.52. 1 147 156. 44 223 2% 27-36 25-30 6. 0 D0. 49. 5 140 150 26. 3 225. 51 75-90 90-05 12. 8 D0. 51. 7 146 199 26. 9 252. 7 2% 28-38 90-95 9. 0D0. 44. 7 126 171 23 4 214 2% 27-39 90-95 13. 2 semi-gel. 50. 1 141 25527 O 246 2 4 27-36 90-95 19. 7 stlfi-gel.

As a more specific illustration of the esterification procedure outlinedabove, the sulfonation of oleic acid was conducted as described inExample 1 using 51.9 parts of variations in the mole ratio of alcohol toacid and in reaction time on the yield and quality of the sodium salt ofmonosulfonated n-propyl oleate.

ESTERIFICATION OF MONOSULFONATED OLEIC ACID WITH n-PROPYL ALCOHOL MolesMoles Wetting Tune Alcohol NaOH Esteriflcation Percent 11;73830116183101 a Clarity C 0101, of 50% o oln. at All Run No pet per 011concenvs Solution Mole Mole on 50% B I (Without Oleie $03 to Time TempSample Bleach) Acid p119 0 p119 p112 1. 25 1. 38 2% 25-40 0. 4 16 7clear. dark orange. 2. 0 l. 16 2% 25-40 6. 4 14 8 D0. 2.0 1.14 2% 45 7.0 15 8 D0. 3.0 1. 15 34 25-90 7. 4 10 6 reddish orange. 3. 0 1. 36 -407. 1 12 10 dark orange. 3.0 1.15 25-40 7.0 10 8 Do. 3.0 1.15 1 25-40 6.8 9. 5 7 5 D0. 3. 0 1. 10 2% 25-40 10. 2 8 6 DO. 5. 0 1. 54 25-40 4. 814 9 light orange. 5.0 1.32 56 25-40 0.0 8 6 D0. 5.0 1.08 2% 25-40 8.5 76 not clear dark orange.

liquid S03 dissolved in 474 parts of liquid S02 and 147 parts ofcommercial 90% oleic acid. After removal of the bulk of the S02, 156parts n-propanol in 52 parts of water (75% alcohol by weight) was addedand the temperature brought up to 75 C. in 12 minutes. After cooling to3540 C. in 10 minutes, the system was evacuated for 10 minutes using awater aspirator pump to remove residual S02. At this time thetemperature was 20 C. and 34 parts of NaOH dissolved in 116 parts ofWater were added to neutralize the product to a pH of 9. The temperatureduring the neutralization never exceeded C.

An azeotropic mixture of alcohol and water was removed followed byremoval of some excess water by distillation. The distillate consistedof 118 parts of n-propanol and 113 parts of water (51% alcohol). Thisdistillate when refortified with pure n-propanol to give a final aqueousn-propanol mixture consisting of As already stated, moreover, themonosulfonated esters can also be neutralized with NHs, alkanolamine,etc., to provide valuable products. For example, after completion of theesterification with n-propanol, amines such as monoethanolamine,diethanolamine, triethanolarnine, etc., were added to neutralize thesulfonic acid group and produce the corresponding substituted ammoniumsalts of monosulfonated n-propyl oleate. After neutralization with suchorganic bases, the excess n-propanol was distilled oif leaving behindwater-free salts of the monosulfonated esters. These salts were clear,fairly mobile, light amber liquids which were freely soluble in waterand possessed excellent surface active properties. The mono, di andtriethanolammonium salts are highly soluble in chlorinated solvents suchas carbon tetrachloride, thus making them of value as surface activeagents in nonaqueous media.

TIM-KS 30F TETEANIQLAMMOfiIUlVI SAL'TS MONOSULFONATED N-PROPYL QLEATE;iOoncentration=;I% in watering room temperature] Wetting E'lime Salt(seconds),

Draves Test monoethantilammonium. Q Q. .1. 3; 5. dlethanolammoniu.m 5; 0trlethanolammonium 5. 0

I EXAMPLEJ Preparaifion of-earboxylic acid esters 'of-mixtures 0fm0n'0-szilf onated mono and poly "unsaturated acids A sample of a commerciallyavailable tgrade ofoleic acid lesspure than .that'usediin Examplelandcontainiqggmoreythan 5% polyunsaturated .carboxyli c-acids wassulfoaated-.as describedinExample 1 and. reactediwith-nprqpauol .asdescribed in Example 6. After-distilling .ofi' theiexcessralcoholr-suflicieut sodium hydroxide was added to bring the pHto 7 and the concentration to 50%. At

this time the 50% aqueous-solution'waswof 'a-darkred color, "and since alighter color was desired, the solution was bleached as describedaboveby .adding suflicient sodium"hydrochloride;solutiori toraisethepH-to 8. The Solution was then of .a light-orange colorwith aclean pleasant smell and possessed very good wetting characteristics asshown'inthe following table:

"WETTING TIMES .'(D RAVES TEST) Percent Na Salt oflvlonosulfonateldji-propyl. 88sec? ;pH 2, sec- Esters in Water onds 26.15 6 5 less 1 2 An' extraction of the 510% aqueous solution .o'flthe'sodium salt of the monosulfonated n-propyl esters prepared from .thisinferior grade ,of .oleic acid i showeduan oil content of onlysl 0%Rosin "acid f6 7 were sulfonated inta manner identical with that inExample 1 and estcrified with 1n-propyl' alcohol "and neumonosnlfonatedv. n-propyl mixture of carboxylic acids showed only;=8i4% ofunreacted-oils. Thewctting'characteristicsnf thiszzproduct :were still:very good although notcasr goodaszthoserobtained with reagentsof'high'qua-lity. Th eaitollowing table gives the wettingcharacteristics found:

WETTING TIMES (BRAVES TEST) onds onds PercentNa'salt ofMonosult'onated'n propyl pHS; sec-' 'pH'2ysec EEStersdn Water"Thefollowing" additional examples illustrate the esterifi cationof-tlie:monosulfonatedcarboxylic acids with-poly and substitutedalcohols:

' In the already described manner 53i6-"grams 7 I803 flis sdlved in 475'n'il. liquid SOrWas fdisc sulfonator at 'an:;equivalent jra'tewith';15.1 grams of commercial grade (90%") oleic acid. After-removal"of the'bulk of-theSOa (temp. 5 C;) 33.2- grams ofiethy'lene glycoll-mole glycolzper mole "of monosulfonate'd oleic 7 acid) 'was added andthe temperature was takenulp '10 60 C; in 8 minutes. The heat"was-removed while stirringwellythe flask-was'partially evacuatedwith-suction from a water "aspirator for 15 minutes. After tliis'fimc,

27 gramsNaOH dissolvedin"100*ml. 'HzO-was-added slowly using anice-water bath 'tog'prevent the temperature fromrising-above "60 5 C.The pH of this -mixturejat*t fiis time-was 6. Four gramsof'NaOH-in'20-ml.H20'were addedtob'ringthepH me. This ,c'lear orange liquidgave V clearso'lutions in water and possessed a'wettingiime 16$ 62seconds *for a023 total-solidssolution (Draves test) a troonrtemperature.

- To the'pro'duct -was ascribed the followingfomnih: V

CuHgz-C0CH;CHOH

. SO Na 0.

EXAMPLE In the previously described manner, 53.6 grams of I liquid 8G3dissolved in 475 ml. liquid SO: were run.

through the disc sulfonator at equivalentfrates with 151 grams ofcommercial grade "(90%) oleic acid. After removal of; the bulkoftheSQzfttemp. 5 C.) 16.6 grams of ethylene glycol (2fmoleslof :sulfonatedoleic acid to L-mole of ethylene glycol) wasadded and the temperaturetaken up 10710 Qjnf. 1D niinutes The heat was removed and while;stirring well, the'11ask was partially evacuated with suction from awater aspirator for 'minutes. At this time 27 grams of NaOH dissolved in100 ml. H2O

, were added s'lowly usin gsan ice water bathrto prevent temperatures''in excess'of 160, C. ThePI-Iaatfthis limewas a tralized in -amanneridentical with that in Example 6. r Extraction of, a solution of asodium salt of the i6 and '9- moregrams ojf'NaDH'in SDmLLI-IiO werenecessary to raise the pH to 9. The clear orange liquid productgaveclearrsolutions in water and was found to have a wettingtime-of-27seconds for a 0.3% total solids solution .(Draves test) atroom temperature.

*To theproduct was ascribed" he following formula:

- o11Hwo ocrn0m-o-o-onm, Q O Na O O Na .EXA MPLE 11 In thegpreviouslydescribed manner53.6 grams of liquid S03 dissolved :in 475 ml. liquidS02 were run through the disc zsulfonator at'an equivalent rate with 151grams or commercial (90%) oleic acid. After removal of the bulk of'lheS02 (temp. 5? C.) 49.3 grams of glycerol ('1 mole-cf sulfonated oleicacid to '1 mole of glycerol) were added and the temperature taken up to75 C. in

1'5 minutes. The heat was removed and while stirring well, the flask waspartially evacuated with suction from a water aspirator for 15 minutes;Twenty-seven grams Na'OH dissolved'inklofl rrilQHzO wereadded slowlyusing anfice .Water bath to keep the temperature lasflllow as possible.Due to the .difiiculty .in stirring and pooriheat transfer; due to thevis'cos'ity.of thef producty-the tempera reddish-orange, ve1 y yiscousliquid gave clear solutions 7 'ture rose as high 1570? C. during theneutralization. flhe pH at this time was 6 and'af ter addingS gramsfNalQI-I dissolvedijin 27,1131. Ha'O-thepI-Iibecame :9; The Clear,

in water and showed ,a wettingtime of j83 seco.nds"o'r a 013%totalsolidssolutlQn (Dr'avesftest)Iat room'tenmerature.

The product was assigned the fo1lowing ,structure:

. V on CuHaz'IF- O GHFOH- GHQOH SOiNa In the previously described manner53.6 grams of liquid S03 dissolved in 475 ml. liquid S02 were runthrough the disc sulfonator at an equivalent rate with 151 grams ofcommercial (90%) oleic acid. After removal of the bulk of the S02 (temp.5 C.) 71.8 grams of diethylene glycol monoethyl ether was added and thetemperature taken up to 70 C. in 12 minutes. The heat was removed and.while stirring. well, the flask was par tially evacuated with suctionfrom a water aspirator for 15 minutes. Twenty-seven grams of NaOHdissolved in 100 ml. H2O were added slowly while stirring and using anice water bath to keep the temperature below 43 C. The pH at thistime'was 6 and 7 grams of NaOH dissolved in 30 ml. H2O brought the pH to9. This yellow-orange liquid gave clear solution in water and displayeda wetting time of 31.5 seconds for a 0.3% total solids. solution (DravesTest) at room temperature.

The following structure was assigned to the product:

SOsNB Thus it will be evident that the monosulfonated unsaturatedcarboxylic acids and their esters produced by the present inventionpossess not only remarkable stability against hydrolysis. and heat butalso outstanding surface active properties, sov that they are eminentlysuited for use in acid, neutral or basic media as dispersing,clarifying, solubilizing, emulsifying, wetting, rewetting and detergentagents. For many purposes the monosulfonated acids themselves are wellsuited, but in other cases their esters may be preferred. In the lattercase esterification can be integrated with sulfonation in a continuousprocess, the alcohol being added during the removal of the S02 from thesulfonated acid and before neutralization. Under these conditions thefree sulfonic acid groups of the monosulfonated acids appear to catalyzethe reaction between their free carboxyl groups and the alcohols, thusgreatly facilitating the esterification.

EXAMPLE 13 In order to demonstrate the emulsifying ability of compoundsembodying the invention, the sodium and triethanolammonium salts ofmono-sulfonated n-propyl oleate (NaPO and TEAPO respectively) were usedin preparing emulsions of the herbicides isopropyl N-(3- chlorophenyl)carbamate (Cl-IPC) and isopropyl N- phenyl carbamate (IPC). herbicidewas dissolved in an emulsifier-inert solvent mixture and enoughdistilled water was added to form about a 1% emulsion of the activeingredient, i. e., the herbicide. The stability of these emulsions wasobserved visually with the following results:

A 0.5 gram sample of the f8 20 ml. samples of the various formulationswere diluted with water to 100 ml. with the following results:

EMULSIFICATION OF VARIOUS INSECTICIDES IN TAP WATER Emulsity- Stabilityof, ing Agent Insecticide Formulation Water Emulsion TEAPO... DDT 25%DDT, 10% approx. 3honrs, TEAPO,and% easily reemnl- Xylene. sifiable.NaPO DDT 25% DDT, 10% Do.

NaPO, and 65% Xylene. 'IEAPO Toxaphene 25% Toxaphene, approx. 2 hours,

10% TEAPO and; easily reemul- 65% Xylene. siflable. NaPO .do 25%Toxaphene, Do.

10% NaPO, and 65% Xylene. TEAPO BHO .12% BHO, 10% Do.

TEAPO,and78% Xylene. NaPO BHC 12% BHO, 10% more than 91 I1 {IalP0, and78% hours.

yene. TEAPO--- Aldrin 28% Aldrin, 10% more than 19 TEAPO, 2% hours.Xylene. NaPO do 28% Aldrin, 10% D0.

NaPO, and 62% Xylene. TEAPO- Dieldrin(88%)- 'l8% Dieldrin, 10% more than21 TEAPO and 72% hours. Xylene. NaPO do 18% Dieldrin, 10% Do.

1NaPO, 72% Xyene.

In the foregoing table, DDT is dichloro-diphenyl-tri chloroethane;Toxaphene is a mixture containing polychloro bicyclic terpenes withchlorinated camphene predominating; BI-IC is hexachlorocyclohexane;Aldrin is the assigned common name for an insecticidal productcontaining not less than hexachloro-hexahydro-dimethanonaphthalene; andDieldrin is the assigned commonname for an insecticidal productcontaining not less than 85% ofhexachloro-epoxy-octahydro-dimethanonaphthalene.

EXAMPLE 14 The emulsifying agents mentioned above (NaPO and TEAPO) are.also effective in Water having a hardness up to about 300 p. p. m., butthereafter begin to lose effectiveness so that one of the knownchelating agents such as Versene or Sequestrene (ethylene diarninetetraacetic acid) should be used, especially above 500. p. p. m. Forexample, regular Versene (ethylene diamine tetraacetic acid) was addedin varying amounts to 2.0 gram samples containing"48% Cl-IPC; 10% TEAPO,i0-% SATISFACTORY EMULSIFIABLE CONCENTRATES OF IPCAND Cl-IPC INDISTILLED WATER Wgight Ratio in A f Active Emulsiiying oncen ateppearance o Compound Agent Solvent Act.Opd:Enn1l. Concentrate stabmty ofWater Emulsmn AgtzSolvt.

NaPO (65%) 1:1*:3 clear light yellow 42 hours. TEAPO (85%) isopropanol.112*:4 clear yellow 22 hours." NaPO (65%) xylene 2:328 cloudy 4 days."TEAPO (85%) "do 2:3:8 1.2 H20 16 hours**-very Slightly broken 6:3*:17 2H2O after 24 hours. Reeruulsifled easi y.

Refers to active ingredient solution-not to active ingredient.

Stable beyond period indicated here, observations were stopped at thispoint.

Similar results were obtained in emulsifying various known insecticidesin fairly soft tap water (40-60 ppm).

methyl isobutyl ketone, 25% xylene, and 7% kerosene, each sample beingthen diluted to 100 ml. with water 19 having a hardness of 1000 p. p. m.The results were as follows: EMULSIFICATION OF Cl-IPC IN HARD WATERUSING VERSENE (REGULAR) AS COMPLEXING AGENT Stability otWater Grams ofVersene Emulsion approximately 1 hour.

more than 42 hours. approximately 17 hours. less than 17 hours.approximately 1 hour.

All ions complexed; theoretical amountof Versene needed to complex allhard ions=0.43 grams. r

Similarly varying amounts of regular Versene were EMULSIFIOATION OFVARIOUS INSECTICIDES IN HARD WATER USING TEAPO AND VERSENE (REG.)

Grams Stability of Water Emulsion Versene Insecticide approximately 1hour.

0. approximately 5 hours. approximately 40 hours, reemulsifled easily.approximately 30 minutes. apprlgximately 4 hours.

approximately 40 hours, reemulsifled easily. apprlgximately 2 hours.

999999999999 tawntmenmpwzou Do. 7 approximately 24 hours, reemulsifledeasily.

For some materials such as C1-IPC, the addition of a small amount of anon-ionic surface active agent such as Renex (a condensation productoftall oil with ethylene oxide) results in better and more stableemulsion, although the agent itself may be an inferior emulsifying agentin the particular system involved. This is shown by the following testsin which the specified amounts of C1-IPC were added to a concentratecontaining 0.2 gram TEAPO, 0.2 gram Renex, 0.4 gram xylene, 0.1 grammethyl isobutyl ketone, 0.1 gram kerosene, and 0.3 gram Versene, and thewhole diluted to 100 ml. with hard water:

Run number 3 was the best emulsion obtained.

20 It will be understood that the invention is not restricted to thespecific acids and alcohols named above by way of examplefnor tothedetails of the illustrativevexamples of the process. .Reference shouldbe had to the appended claims for a definition of thelimits of theinvention.

What is claimed is:

1. A process for the production of monosulfonated unsaturated aliphaticcarboxylic acids which comprises sulfonating an unsaturated aliphaticcarboxylic acid with sulfur trioxide dissolved in liquid sulfur dioxidein the proportion of 1.04.25 moles of sulfur trioxide per mole ofunsaturatedacid, and separating the sulfur dioxide from the sulfonatedmaterial comprising free carboxylic acid characterized by retention ofat least 40% of the unsaturation prior to sulfonation and byapproximately one molev of organically combined sulfur trioxide per moleof acid. 7 U I 2. A process as defined in claim 1, whereinthe sulfonatedmaterial is neutralized by the addition of a base to the sulfonationmass.

3. A process as defined in claim 2, including the step ofseparatingunsulfonated materials from the neutralized sulfonatedmaterials by solvent extraction'of themass.

4. A processas'defined in claim l, including the step of esterifying thefree carboxylic acid groupsof the sulfonated material by adding atleast, one mole of an alcohol to the sulfonation mass, said alcoholbeing selected from the group consisting of substituted andunsubstituted primary and secondary monohydric and polyhydric alcohols.7

5. A process as defined in claim 4,.wherein the esterified sulfonatedmaterial is neutralized by the addition of a base to the reaction mass.

6. A process as defined in claim 5, wherein sufiicient base is added to.raise the'pH of the reaction mass to about 5.0-7.0, after whichsufficient hypochlorite is added further to raise said pH to about8.0-9.0."

References Cited inthe file of this patent UNITED STATES PATENTS YWerntz May 6, 1941

1. A PROCESS FOR THE PRODUCTION OF MONOSULFONATED UNSATURATED ALIPHATICCARBOXYLIC ACIDS WHICH COMPRISES SULFONATING AN UNSATURATED ALIPHATICCARBOXYLIC ACID WITH SULFUR TRIOXIDE DISSOLVED IN LIQUID SULFUR DIOXIDEPER MOLE PROPORTION OF 1.0-1.25 MOLES OF SULFUR TRIOXIDE PER MOLE OFUNSATURATED ACID, AND SEPARATING THE SULFUR DIOXIDE FROM THE SULFONATEDMATERIAL COMPRISING FREE CARBOXYLIC ACID CHARACTERIZED BY RETENTION OFAT LEAST 40% OF THE UNSATURATION PRIOR TO SULFONATION AND BYAPPROXIMATELY ONE MOLE OF ORGANICALLY COMBINED SULFUR TRIOXIDE PER MOLEOF ACOD.